Angiopoietin-2 is required for postnatal angiogenesis and lymphatic patterning,and only the latter role is rescued by Angiopoietin-1

VEGF and Angiopoietin-1 requisitely collaborate during blood vessel development. While Angiopoietin-1 obligately activates its Tie2 receptor, Angiopoietin-2 can activate Tie2 on some cells, while it blocks Tie2 activation on others. Our analysis of mice lacking Angiopoietin-2 reveals that Angiopoietin-2 is dispensable for embryonic vascular development but is requisite for subsequent angiogenic remodeling. Unexpectedly, mice lacking Angiopoietin-2 also exhibit major lymphatic vessel defects. Genetic rescue with Angiopoietin-1 corrects the lymphatic, but not the angiogenesis, defects, suggesting that Angiopoietin-2 acts as a Tie2 agonist in the former setting, but as an antagonist in the latter setting. Our studies define a vascular growth factor whose primary role is in postnatal angiogenic remodeling and also demonstrate that members of the VEGF and Angiopoietin families collaborate during development of the lymphatic vasculature.     

A compact sunflower line produced after cross Helianthus annuus x Verbesina encelioides

Intergeneric cross was made between the cultivated sunflower inbred line HA89 and an accession of wild Verbesina encelioides tolerant to drought and high temperature. The line was a BC₂F₅ progeny. The most remarkable feature of the plants was their compact architecture due to short petiole length and also, rather specific bright-yellow inflorescences. Similar plant architecture did not exist in either the wild or the cultivated parent. For sunflower, it is considered as a favourable and potentially useful adaptive trait. The line was multi-branched of medium type branching and possessed good agronomic characteristics. The overall characteristics of HA-VERBENC line make it a useful plant material for research on wide hybridization.